Cycloidograph.



`No;$42,443. PATBNTED JAN.. 29, 1907.

J. P'. oooLEY.'

oYcLoIDoGRAPH.

APPLICATION FILED NOV. 15. 1902.

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r .35 llilllllllllilllllllllllllllllmlllllllllmlll Y YPATBNTBD JAN. 29, 1907. J. P. cooLEY.

GYCLOIDOGRAPH. PPLIGATION FILED NOV. 15,. 1902.

10 SHEETS-SHEET 2.

PATBNTBD JAN. l29, 1907.

J. F.. cooLEY. GYGLOIDOGRAPH, APPLIUATION FILED NOV. 15.1902.

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PATENTEDl JAN. y29, 1907.

J. F. COULBY. CYCLOIDOGRAPH.

APPLIGATION FILED N0v.15.1902.

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LNo. 842,447.

PATENTED JAN. 29, 1907.

J. F. GOOLEY. v

GYCLOIDOGRAPH. APPLIGAT'ION FILED Nov.1s.19oz.

0 SHEETS-SHEET 6.

No. 842,447. PATENED JAN. 29, 1907.

J. P. COOLBY.

` GYGLOIDOGRAPH.

APPLICATION FILED NOV. 15.1902.

10 SHEETS-SHEET 8.

No. 842,447. PATENTED JAN. V29, 1907;

J. F. comm.

GYCLOIDOGRAPH. APPLIUATION FILED 11011.15. 19024 10 SHEETS- SHEET 9.

"fri 842,447.

@WMM/ 1 PATENTED JAN. 29, 1907.

J. F. GOOLEY.

GYCLOIDOGRAPH.

APPLIOATION FILED Nov. 15. 1902.

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boss 15, of .the offset-indicator plate 16 andl UNITED STATES PATENT oEEIoE. -JoHN.'FRANoIS CooLEY, 0E BOSTON, MASSACHUSETTS, AssIGNoR oF ONE-'- HALF TO COOLEY EPICYCLOIDAL ENGINE DEVELOPMENT COMIIANY,

OF JERSEY CITY, NEW JERSEY, AND BOSTON, MASSACHUSETTS, A COR- PORATION OF yNEW JERSEY.

'CYCLOIDOGRAPH.

Specication of Letters Patent.

Patented Jan. 29, 1907.

Application illed November 15,1902- Sei'ial Nfo. 181.518.

vdescribing cycloidal curves and is illustrated in the accompanying drawings, in which- Figure 1 is afront elevation of the device. Fig. 2 is a side elevation. Fig. 3 is a lan. Fig. 4 is a vertical section on line 4 4, Flg. 3. Figs. 5, 6, 7 8, and 9 are plan views of the soriber-head. Figs. 10 to 24, inclusive, 'show hypocycloidal, and Figs. 25 to 39 inclusive, show epicycloidal curves made by the instrument.

Referring to the drawings, a base -1 has mounted thereon posts-2 3, one of which, 2, carries a cross-bar 4, in which are rotatably mounted two vertical spindles 5 6. The spindle 5 carries a circular table 7 at its upper end, upon which is detachably secured paper 8, by means of clips 9." At its lower lend the spindle 5 has keyed thereon a gear 10, meshing with a transmission gear 11, loosely mounted on the post 2. The gear 11 `meshes with a gear 12, keyed on the lower end of spindle 6 by means of a screw 13. The bar 4 carries at one end a hollow pedestal 14, upon which is mounted in succession the the boss 1.7 of the arm 18. The oHSet-indicator plate is permanently set by screw 19.

v The arm 18 is adjustably set-by a thumbscrew 20. An offset-indicating needle 21 is secured to the boss 17. A slotted arm 22 is rotatable, adjustably mounted upon the upper end of the boss 17, and is controlled byl the thumb-screw 23.

The arm 18 carries the vertical spindle-24. This spindle is upwardly spring-pressed by means of a compression-spring 25, acting between the boss 26 and the cap 27, keyed to the spindle 24. .Upon the tapered lower end 28 of the spindle 24 is pressed a head29.

. This head 29 carries one or more radial arms 30, bearing spring-actuated scribers 31, of ordinary construction. Other heads, Figs. 5, 6, 7, 8, and 9, carrying a varying number of radial arms are sup lied and are adapted to lit upon the lower endP of the spindle 24. When of different sizes.

the head carries a plurality of arms, Figs. 5 to 9, they are of equal length and equiangularly spaced about the head.

'lhe arm 18 is of such length that by rotatably adjusting it on the pedestal 14 the axis of the spindle 24 may be made coincident With that of spindle y5. In this position of arm 18 the offset is indicated as zero by the needle 21 on plate 16. Upon the upper'end of the spind1e24 is keyed a gear 32 by the.

screw-threaded boss 33 upon the crank 34, upon which is placed a handle 3 5 for operating the device. l Thevspindle 6 is reduced in size intermediate its length and is held from gravitythrust by a screw 36 playing in an 'annular groove 37 in its lower head. On the upper end of the spindle 6 is keyed a gear 38 by means of the thumb-nut 39. A transmission-gear 40 meshes with the gears 32 38 upon the spindles 24 6. This transmissiongear 40 is mounted upon a stud-bolt 41, slidably. adjustable in the slotted arm 22 and fastened in position by a thumb-screw 42.

The gears 32 38 are replaceable by gears 43 These when not in use are conveniently placed u on a stud-bolt 44, projecting from one of t e posts 3.

Theo eration of the instrument is as follows: Tlie gears 10 11 12 are merely transmission-gears of equal Size, and spindles 5 6 therefore rotate at the same speed. Gears 38 32 on spindles 6 24 are of different size and therefore determine the correlative speeds of the spindles 6 24 and therefore of spindles 5 24. The gear 40 is merely a transmission-gear. In placing these gears a gear 38 is first keyed upon spindle 6. The gear 40 is then slid along the slotted arm 22 until it meshes with the gear 38. It is then iixed on arm 22 by the thumb-screw 42. Arm 22 is then rotated about the boss 17 until the gear 40 meshes with a gear 32, previously keyed in place on spindle 24. Arm 22 iS then keyed to oss 17 by thumb-screw 23. The axes of the two slpindles 5 24 aregiven 'fixed position of paral elism by rotating arm 18 about its bearmg on the boss 14 to give any desired oifset or distance between the parallel axes, and the arm 18 is then secured by the thumb-screw 20. Paper 8 having been placed on the table 7 by means of cli s 9, the crank 34 is rotated and a downwar pressure exerted upon the crank-handle 35, com ressing the spring and bringing the scri ing-points in contact with the paper, so. as to describe various curves thereon. The spring-scribers 31 also aid in simultaneous and uniform action of the scribing-points T he correlative speed of scribers and table determine the character of the curves formed.

The im ortance of this invention is manifestparticu arly when the correlative s eeds'are expressible by consecutive numera s, as table-speed of 1 to scriber-'speed of 2, or table-speed of 4 to scrib'er-speed of 3. In these instances cycloidal curves may be formed. It is found that hypocycloids are formed when the table has the lower speed and epicycloids when the table has the higher s eed. l

pAs to the number of scribing-points that may be used it is found that one scriber will always roduce a single closed curve. It is also to e noted that the greatest number of scribers that can be used is e ual to the consecutive numeralA representing the tablespeed, and the single closed curve formed will be the common path of all the scribers. As hereinbefore implied, these scribers are in general equiangularly s' aced about their .axis of rotation, and as t ey describe a common path it is obvious that fewer than the greatest number of scribers may be used, and

these then Will not be equiangularly spaced about the axis of rotation unless the number so used is a numerical factor of the greatest number that can be used-that is, in the case of Fig. 9 any number of the six scribers may be used, and these cannot be equiangularly spaced unless either two or three of them are used, in which case they may be so spaced. My invention contemplates the use of .any desired number of scribers up to and including the greatest number that can be used. Applying these principles to specific data, it is found that curves are formed as follows:

Hypocycloz'ds.

I l G r e a. t e s t Scriber Table speed. g number of Curve. speed scribers.

2 1 2 lobe (Figs. 10-14.) 3 2 l 2 3 lobe (Figs. 15-19.) 4 3 4 lobe (Figs. 2li-24.)

Epicyclois.

G r e a t e s t Scriber l Tables eed. number of Curve. speed' p scribers.

1 2 i 2 1 lobe (Figs. 25-29.) 2 3 i 3 21obe (Figs. :so-34.) 8 4 4 3 lobe (Figs. 35-39.)

The six classes of curves enumerated are illustrated in the drawings by iive examples of each showing the effect `of a lchange in the oflset between the axes of spindles 5 24 from zero, Figs.- 10, 15, 20, 25,30, and 35,to a maxi-' or clearness, the circutheir center of rotation, the small full circle.

The arms radiating to the scribers are represented by dottedlmes. The scribing points are represented by small full circles at the extremities of the arms. The greatestnumber of scribing-points is shown in every case.

Having thus described the nature of my invention and set forth a construction embodying the same, what I claim as new, and desire to secure by Letters Patent of the United States, is

1. Ina cycloidograph, a table, a head, both rotating in the same direction on separate parallel positionally-ixed axes at correlative speeds expressible by consecutive numerals, gearingconnecting the table and head, a plu` rality of scribers carried by the head in contact with the table and at equal radial distances from its axis of rotation, and means for rotating the rotatable parts.

2. In a cycloidograph, a table, a head,both rotating in the same direction on separate parallel positionally-ixed axes at correlative speeds expressible by consecutive numerals,

gearing connecting the table and head, a plurality of scribers carried by the head in contact with the table and at equal radial distances from its axis of rotation and equiangularly spaced tliereabout, and means for rotating the rotatable parts.

3. In a cycloidograph, a table, a head, both rotating in the same direction on separate parallel positionally-ixed axes at correlative speeds expressible by consecutive numerals,

Vgearing connecting the table and head, a plu- JOHN FRANCIS COOLEY.

Witnesses:

A. L. MESSER, l C. A. STEWART.

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